Card readers are electronic devices which may include electromechanical components. Such card readers are commonly provided in vending machines, point of sale terminals, etc. A consumer inserts a stored value "smart card", credit card or debit card into the card reader. Electronic circuitry provided within the card reader reads and processes information which is stored on the card, and may also update information on the card. This information enables the owner of the vending machine, point of sale terminal, etc. to obtain payment for products or services dispensed to the consumer. Card readers are also commonly used in access control systems to authenticate the card holder, and/or to provide access to buildings, parking garages, etc.
The present invention is directed to card readers adapted for use with so-called "smart cards", particularly card readers used in unattended point of sale ("UPOS") applications in which no human attendant is present to monitor, assist or otherwise supervise operation of the card reader or the associated vending machine, point of sale terminal, etc. An electronic "chip" on the smart card stores a value representative of a pre-paid monetary amount. The chip includes memory registers, and may also include a microprocessor. In a transaction based on a stored value smart card, a consumer inserts a smart card into a card reader. The card reader must not only read the monetary value stored on the card, but also cause the card's stored monetary value to be updated with a new value. The new value is the previously stored value minus the value of whatever purchase the consumer makes via the vending machine, point of sale terminal, etc. associated with the card reader into which the card is inserted.
In order to determine what value to subtract from the previously stored value to yield the new value, the card reader must know the value of the purchase made by the consumer. Modern vending machines and other UPOS devices are capable of dispensing products or services of different values. Accordingly, the value of the consumer's purchase may remain unknown until the consumer makes a purchase selection by actuating controls (extraneous to the card reader) such as push buttons or other controls provided on the vending machine or other UPOS device. The purchase price information which these controls provide is made available electronically to the card reader's circuitry. A time "window" of several hundred milliseconds, or even up to several seconds duration, can occur between the generation of the price information by the controls and the updating of the smart card with its new value.
The aforementioned window can be exploited by unscrupulous persons to obtain products or services without payment. In particular, when the consumer actuates the extraneous controls as aforesaid to make a purchase selection, the product or service is dispensed to the consumer without delay. At this point, the card reader's processing circuity has read the monetary or other value stored on the card, verified that such value is greater than or equal to the value of the purchase selection made by the consumer, and signalled the vending machine or other UPOS device to dispense the product or service. But, the card reader does not finish updating the card with the new value until some time after the product or service is dispensed. An unscrupulous person may withdraw the card from the card reader before it is updated with the new value.
The solution is to prevent withdrawal of the card from the card reader until after the card has been updated with the new value. The prior art has evolved a variety of pin lock mechanisms for preventing withdrawal of cards from card readers. Pin lock mechanisms operate by moving a pin in front of the card after the card has been inserted into the card reader. The pin blocks a portion of the card reader's card insertion slot, preventing withdrawal of the card from the card reader. After the card has been successfully updated with the new value, the card reader actuates the pin lock mechanism to retract the pin, whereupon the card may be withdrawn from the card reader. However, pin lock mechanisms are subject to a variety of problems. They are often mechanically complex, difficult to manufacture and difficult to maintain in reliable working order.
In some cases, pin lock mechanisms may fail to release the card to the consumer upon successful completion of the transaction. For example, pin lock mechanisms are often mechanically actuated by insertion of a card into the card reader, locking the card inside the card reader. Upon successful completion of the transaction, the card reader electronically or electromechanically actuates the pin lock mechanism, releasing the card as aforesaid so that it may be withdrawn from the card reader by the consumer. But, in the event of a power failure, the card reader can not be actuated to release the card unless standby battery power is available. Even if standby batteries are provided, the batteries may lose their charge. The consumer may thus lose the card and its entire stored monetary value, or at least be deprived of the card until trained service personnel intervene to manually override the pin lock and release the card.
Similarly, a consumer may fail to notice that a card reader equipped vending machine or other UPOS device is out of service and insert a card into the card reader. Insertion of the card may mechanically actuate the pin lock mechanism as above, locking the card inside the card reader. Because the vending machine or other UPOS device is out of service, and in the absence of standby battery power as aforesaid, trained service personnel may have to intervene in order to override the pin lock mechanism and release the card to the consumer.
A further difficulty is that physical limitations restrict the space which a pin lock mechanism can occupy within a card reader. This constrains the range of mechanical movement of the parts which make up the pin lock mechanism, consequently reducing the force with which the pin lock mechanism can retain the card. If the card is not retained with sufficient force, an unscrupulous person may defeat the pin lock mechanism by forcibly withdrawing the card from the card reader.
Pin lock mechanisms can also be compromised by cutting way part of the card's plastic substrate so that the pin lock mechanism is bypassed as the altered card is inserted into the card reader. This affords an opportunity to withdraw the card from the card reader before it can be updated with the new value, as noted above. Another tactic sometimes used by unscrupulous persons is to slide a thin piece of paper into the card reader, over the card, after the product has been dispensed, but before the card can be updated with the new value. The paper disrupts the required communication between the card reader and the card, preventing updating of the card with the new value.
Since each card has a unique identifier, it is potentially possible to address the foregoing problems by maintaining a database of cards which have been used in fraudulent circumstances and subsequently refusing to honour such cards. However, it is preferable to do everything possible to prevent fraudulent activity of this sort in the first place. The present invention provides a card reader card capture clamp which is directed to attaining that objective and to overcoming the foregoing problems.
Some smart cards also have a magnetic strip along one side of the card. Information stored in the strip is read by "swiping" the card's strip past a suitable read head. Although the present invention can be used with such cards, the benefits of the invention are generally inapplicable to such cards.
The prior art has evolved some card clamping devices. For example, U.S. Pat. No. 5,089,694 Zerfahs et al discloses a card reader having a mechanism for clamping a magnetic strip type card as a read/write assembly is moved past the card. Zerfahs et al do not appear to address the aforementioned problems in relation to electronic chip type smart cards. U.S. Pat. No. 5,517,013 Bradbury discloses a card reader having a motor-driven mechanism for clamping an electronic chip type smart card. Bradbury does not appear to address all of the foregoing problems.